I may be looking at a generator next week. The only info I have so far is that it's an Onan 17.5KW water cooled motor with 4300 hours of use. I would be converting it to run on grease to help lower utility bills and down the road who knows maybe charge a battery bank. I do not know the make of motor on the unit, so if anyone knows what it could be and if would take to grease well please let me know. I just got a notice from my utility company and their raising rates agian. The owner wants $1500.00 for the gen., if it checks out well I may buy it, what do others think?

Most generators will run on WVO if converted properly. I can sell you a controller that will switch back to diesel periodically (with this interval programmed by you.) This is useful for getting long life from a generator, as they tend to load up/soot up/coke up on WVO, and frequent diesel flushes will help.

The fact that the Onan is water-cooled makes it easier to convert - you can use coolant to heat the tank, the filter and to plumb to a flat-plate heat exchanger.

Here are some other tips for running a generator successfully on WVO:

Running Generators Successfully on Waste Vegetable Oil

1. Run them at close to full load - add banks of electric baseboard heaters, etc. if necessary. A diesel engine that’s idling will tend to “load up” and this eventually can foul the injectors, leading to a poor spray pattern and incomplete combustion, and incomplete combustion can result in a cascade of problems.

2. Flush on diesel 2x a day (or more) and run on diesel at full load for 10-15 minutes 2X/day

3. Heat the WVO well. Hotter is better; that is, the hotter WVO will atomize more finely in the combustion chamber, and it’s this fine atomization/small droplet size that is more apt to combust completely.

Incompletely combusted WVO is a bad thing and could ruin an engine.

If you haven’t purchased your generator, chose one powered by a water-cooled engine, rather than air cooled. Not only will it be quieter, but you can use the hot coolant to heat the fuel with either our Vormax or VegMax coolant-heated fuel filters, plus use a HotFox in the vegetable oil tank and use a HotPlate coolant-fuel heat exchanger for even hotter fuel.

If the generator has a 12-volt alternator, you can also run our Vegtherm 12-volt inline fuel heater.

3 - 3-port solenoid fuel selector valves and a controller will prevent cross-contamination of the diesel tank with WVO.

If it’s possible to find a generator with indirect-injection or pre chamber engine, this is preferable to the more common direct injection engine, but not essential.

I would pass on the Onan and look for a lower speed diesel genset like a Listeroid.

I agree with Craig on most of what he suggested (many of which is what I suggested years ago) except for the Vegmax/vormax/vegtherm being needed. A 120v "vegtherm" can be made for under $25...and a 120v heated filter can be made for under $100.

Nor do I see any advantage in running lubramaloy or using synthetic lube oil. Use an inexpensive diesel oil and change it frequently. If you have ANY lube oil polymerization it is time for a ring job. And you can test for THAT very easily.

Once a month lube oil lab analysis is a waste of money. Once every 6 months should be sufficient.

Don't bother trying to avoid soy oil.

If you plan to run the genset over 12 hours per day invest in a centrifugal filter (like the Dieselcraft) to keep the lube oil very clean.

And I reccomend LP fumagation over switching to diesel twice a day for 15 minutes. It is simple to set up a cheap controller for this.

But before you purchase any generator check into what your household power requirments are..how much you can reduce this..and if there are any subsidies available for renewable energy production.

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WVO life pending still grrrr
Coach George
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Originally Posted by anvil of Pirate4x4.com
[i]your very informative reply has been noted. I think this is the same type of logic you used to draw your conclusi

Thanks for the replies, lot of good info and sugestions.
I went to look at the generator this morning, it is big, and I am worried it would consume alot of fuel. Alot of fuel means alot of time collecting and filtering. The engine seemed to start and run well but it had no muffler and was very loud, the antifreeze and oil looked good. The motor has "ONAN" on the crankcase but I think it is a Cummins motor,the model is 17.5RDJF-3CR/1AD ser.# I850776791 If anyone can dicefer this info I would appriciate it. It is single phase 120/240V 60 HZ. 73 AMPS 1800RPM, The generator had been hard wired so there was no way to know if it was producing electricity with out a multimeter. I will probably not buy it. If my electric co. allowed net metering or if I had a battery bank to charge it would probably serve me well.

Even if you have net metering, there is no hooking a generator to the grid unless its a very expensive (>$100,000) synchronous generator which matches the grid voltage, frequency and phase.

Charging a battery bank and using an expensive synchronous inverter to feed the grid is possible but not cost effective, since the wear & tear on the batteries & genset will cost more than you get paid for the power.

If your utility allows net metering you may be able to hook up an induction generator for feeding power into the grid. An induction generator is simply a 1 or 3 phase AC motor with the capacitors removed. The generator receives excitation voltage from the grid so it will not generate when grid power is lost. Since the excitation is controlled by the grid the phase and voltage remain in lockstep with the utility. You run the generator faster than synchronous rpm to pump amps back into the system. It works.

Originally posted by SunWizard:
Around here every grid-tied installation needs to be electrical code approved and inspected before turning it on. I don't think a home modified motor with capacitors cut would meet codes anywhere.

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WVO life pending still grrrr
Coach George
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Originally Posted by anvil of Pirate4x4.com
[i]your very informative reply has been noted. I think this is the same type of logic you used to draw your conclusi

Around here every grid-tied installation needs to be electrical code approved and inspected before turning it on. I don't think a home modified motor with capacitors cut would meet codes anywhere.

That almost sounds like when naysayers said an engine oil centrifuge wouldn't work to clean wvo. lol

My utility suggested it as part of their net metering program. Inspected, approved and generating the power to send this email and to run my sunwizard dieselcraft filtering and dewatering rig, which I like a lot.

My utility suggested it as part of their net metering program. Inspected, approved and generating the power to send this email and to run my sunwizard dieselcraft filtering and dewatering rig, which I like a lot.

How much did the induction generator cost? Now is this generator something to be used as a generator as in put blades on it, hoist it onto a tower and call it a windmill, or is it somethign that you would only use to send juice to the grid by hooking an electric motor up to it mechanically that is fed from your battery bank? I guess I am asking is it to 1)make juice and sync juice or 2)just to sync juice?

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Bill

The more I learn, the more I realize just how much more I need to learn.

The induction generator is just an AC electric motor with the start circuit disabled and capacitors removed. I am on a single phase line so use single phase motors. These can be had up to 10HP. Northern Equipment has a 7.5HP for $599. I am sure you can find cheaper new ones or even used machines. Supposidly 3 phase motors are cheaper and they come in larger sizes, but I have not investigated since it would not work with my service.

My prime mover is a diesel engine running on WVO but some of the wind guys are using induction generators as well. The big issue is you have to run the generator above synchronous RPM. In the case of an 1800 rpm motor, typically rated at 1740-1750 rpm you might need to drive it at about 1850rpm to generate electricity. If the speed drops below synchronous (1800rpm) the generator reverts to being a motor again. Also, if the generator overspeeds it will stop producing electricity. This narrow rpm band is not an issue for the diesel engine but adds some control complexity for the wind guys.

If I understand your last question correctly, it makes synchoronised juice, but only in the presence of grid power. There are ways to make it into a stand a lone generator with proper sizing of capacitors but it is way beyond my skill level.

Most generators will run on WVO if converted properly. I can sell you a controller that will switch back to diesel periodically (with this interval programmed by you.) This is useful for getting long life from a generator, as they tend to load up/soot up/coke up on WVO, and frequent diesel flushes will help.

But an engine in an F-250 is not efficient. Especially making only 10HP. Hooking that generator up to an efficient diesel might be worth it. Maybe a 12 horse diesel with a few pulleys to ramp up the speed appropriately.

__________________
Bill

The more I learn, the more I realize just how much more I need to learn.

I'm sure someone here knows the answers to the questions bebopping around in my head.

I'm looking into getting a generator for backup power, and perhaps to sell WVO generated juice back to the grid. I know it sounds kind of far fetched, but I have a chance to get a low-hours 7.5KW onan diesel generator for about a grand. I figure if I can get 6KW into the grid, that's about a buck an hour. If I run it six hours a day, that's about 5 gallons of WVO, and about 4.50 worth of electricity. In theory it will pay itself off in a little over six months. I would probably only run it from April through October since during the winter season I don't have an excess of fuel since I heat my house with WVO.

A few questions though.

Can I rig the generator to run synchronous to the grid? Are these typically brushless induction type generators where I could in theory have the field excited by the grid so that the power generation matches up?

If I need to buy a synchronous inverter, that pretty much kills the idea.

Second... Are these hearty enough engines that I could run them off of WVO? They are water cooled, so I could heat it relatively easy. For probably about 150 bucks I could do it cheap but right.

__________________
Bill

The more I learn, the more I realize just how much more I need to learn.

I wouldn't want the noise of it operating since I spend a lot of time outdoors. Your neighbors may object as well.

Most generators are not able to be synchronous. But more important than that is your power company rules on what generators they allow to grid interconnect, power quality and safety features, etc. You should check with them, that will limit your choices and increase costs greatly. They generally will want a UL approved synchronous inverter or generator, very expensive. I doubt they will allow a do-it-yourselfer modified/hacked generator or motor (even if you do understand how to hack it to excite the field.)

Also check if they have net metering. Many places only pay 1 cent per KWH for the power you generate, while they charge 10 cents.

I'm looking into getting a generator for backup power, and perhaps to sell WVO generated juice back to the grid.
I figure if I can get 6KW into the grid, that's about a buck an hour. If I run it six hours a day, that's about 5 gallons of WVO, and about 4.50 worth of electricity. In theory it will pay itself off in a little over six months.

Myself, I would buy the genny for the reasons you want it and keep the hours down so it is in the best condition possible for when you need it.

In your payback calculation, did you take into account the cost of things associated with putting big hours on the thing like filters, oil and general maintenance? I think at $1 an hour, you'd be pushing it to break even, free fuel and all and what about the depreciation cost of running big hours up on the genny itself. If you have a problem with it, the time to recoup the repair costs may not pass before you need to do something else!

I don't know what the situation is in your area but I'm guessing that there is a likelyhood that you could get a $1 a gallon just for the cleaned oil you would burn in the genny if you offered it for sale which would give you a return of $5 a day equivelent with no other costs or depreciation!

I think for minimal returns like that, it isn't worth while wearing your genny out let alone the hassle. Buy it, keep it for when you need it and sell the oil you would have burnt and recoup your investment that way.

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* I STILL have never made biodiesel, but I have been present when it has been made. *
Local Self appointed and opinionated Veg oil wizard explaining how he knows so much about bio and can answer every detailed forum question on the subject b